Audi combines performance and style with the world's cleanest diesel

Audi combines performance and style with the world's cleanest diesel

Wheels

Audi Q7 3.0 TDI - first look
By: Jim Robinson

NIAGARA-ON-THE-LAKE: Audi can't seem to put a foot wrong. The fabulous R8 sportscar has won virtually every Canadian 2008 new car award there is and the company simply can't get enough of some models like the S5 and A5, not to mention the R8, to satisfy demand.

But as Audi goes from strength to strength in terms of performance and style, there is a new trend emerging and that's the power of diesel.

In the first quarter of 2009, Audi will be offering its 3.0-litre TDI (turbo diesel injection) V6 engine in the Q7 SUV that gets an estimated 9.8L/100 km (combined) and can carry you close to 1,000 km on one tank.

It's not just another fuel saving diesel. Audi claims it is the cleanest diesel in the world. For example, the combustion cleaning process lowers nitrogen oxide by up to 90 per cent.

Gunter Schiele, who will be Audi's front man and bringing the TDI message to North America, told me the latest TDI is 30 per cent more fuel efficient than the TDI of 1995. The current engine also has double the power of the first generation and 70 per cent more torque.

As fitted to the version I drove recently, the engine produces 221 hp and no less than 406 lb/ft of torque - 100 per of which is available between 1,750 and 2,750 rpm. Even though this is a 3.0-litre V6 that's more torque than a 6.0-litre V8 Hummer (365 lb/ft).

And if that's not enough for you, the Q7 in Europe comes with a 4.2-litre V8 TDI at 326 hp and 560 lb/ft or an astounding Q7 V12 TDI with 500 hp and, get ready, 737 lb/ft.

The Q7 TDI has a six-speed automatic transmission and Audi's renowned quattro all-wheel-drive system that is one of the best in the world.

On one (26 gallon) tank, the TDI Q7 will easily carry you 950 km between fill ups and all the while in the sumptuous surroundings of the Q7's premium luxury appointments.

Audi executive vice-president, Diego Ramos, chatting during the introduction at Niagara-on-the-Lake, said TDI is a cornerstone for the future of Audi in North America.

He said TDI technology was introduced by Audi 19 years ago in Europe. Now more than half of all Audis sold there are TDIs. That's because Europeans have realized they get far more torque than a gasoline engine, while using less fuel. In some countries like Holland, 80 per cent of vehicles are diesels.

Ramos said Canada and North America are now ready for the TDI, not only because of the seemingly unstoppable rise in the cost of fuel, but also because the technology is so clean.

In fact, his biggest concern is being able to get enough of the Q7 3.0 TDI at a target launch in early 2009 and also of the A4 TDI sedan possibly by 2010-2011.

So what makes the diesel so attractive to the Europeans but not to us?

First, of course is the cost of fuel. When we paid 50-60 cents a litre for gas that was one thing. But at $1-plus per litre, that's quite another. Also diesel can be made from vegetable or grain matter, so it uses a source of power that does not depend on the whims of people half a world away.

But the big thing is the perception diesels are noisy and they spew out clouds of black soot.

And that used to true, but no more.

Stand in front of the TDI when it starts up and there is a muffled sound but that's about all. As for billowing black exhaust, there wasn't any and I was watching for it.

Driving around the Niagara area on expressways and back roads proved the Q7 TDI to be responsive to the pedal with very little engine noise being heard, and definitely none of that hammer-and-tong clatter you hear on the big rigs. At 80 km/h the tach was reading just under 1,200 rpm. Hit the pedal to pass and there was no turbo lag you came to expect on turbo diesels. On the highway, passing gave the sensation of acceleration more like a jetliner taking off.

So how is all of this possible?

The system is based on fuel injectors that operate at 29,000-psi (2,000 bar), gas recirculation with two intercoolers and pressure sensors pioneered by Audi that control the combustion process. The turbo with variable vanes adjusts for the best boost depending on load.

It is fed into a catalytic converter where gases are combined with AdBlue, a urea solution, that changes into ammonia with heat and that splits the nitrogen oxide into simple hydrogen and nitrogen.  

The biodegradable AdBlue is carried onboard in a separate container that is replenished at the dealership during routine service appointments. Sensors gauge the AdBlue required. A bonus is the efficiency of the system will remain functioning perfectly throughout the lifetime of the Q7.

And because the injectors can infinitely and instantly supply the correct fuel/air mixture for the most efficient operation, diesel "clatter" is virtually eliminated. It is aided by the architecture of the engine block, that is extensively "ribbed" to quell internal vibrations and is 15 per cent lighter than cast iron due to its use of vermicular graphite cast iron.

What I noticed was how fast the engine starts. Before the TDI, you had to wait for the glow plugs to heat up the cylinder before combustion could begin. Often it was 10-20 seconds before the glow plug indicator light would go out. With the TDI, its Quickstart plugs hit 1,800 degrees Fahrenheit in two seconds.

Being an Audi, the performance of the TDI system is matched by the quality and style of the overall package.

On the 3.0-litre TDI I drove, all the Audi touches like the amber interior illumination and the finest leather and the simplest infotainment system I've come across are there. With the Audi quattro all-wheel-drive system, the partially snow cleared roads atop the Niagara Peninsula presented no problem at all.

Interesting, with all that torque, you'd expect the vehicle to step out under load, but quattro, electronic stability control and traction control make all that a thing of the past.

I'm guessing that at the normal amount of city/highway driving I do, I'd be looking at topping up the tank about one a week. Driving any equivalent power gasoline SUV and at $1-plus per litre cost of gas, it would sure skew my buying decision in favour of a diesel, assuming I could afford one.

Because the Q7 3.0 TDI is about a year away, Ramos could not be specific about the extra cost for the diesel over the gasoline engine. However, pricing should be somewhere midway between the Q7 3.6-litre ($54,000) and Q7 4.2-litre ($69,900) gasoline models. Assuming TDI technology proves as attractive as Audi expects, resale values should also be high.

Making this engine available in the Q7 first makes sense because it offers seven seats, more than enough towing power for boats and/or trailers, and of course, is a luxury SUV that North Americans hunger for.

With its ultra low emission classification and its more economical use of fuel, the story of TDI is just starting to be written.

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